The algae Vaucheria litorea are able to carry out photosynthesis; however, isolated chloroplasts from V. litorea are not. Researchers have determined that the DNA within the chloroplasts contains the genes required for photosynthesis. Many of the additional genes needed to sustain chloroplast function are located in the nucleus. To investigate the genetic requirements for chloroplast function in the green sea slug, Elysia chlorotica, researchers sequenced the psbO gene found in V. litorea. The psbO gene encodes for part of the water-splitting complex in the light-dependent reaction during photosynthesis. The researchers then determined which cells, cell parts, and developmental stage of the green sea slug, if any, also contain this gene. The data from their investigation are shown in the table.

Question

The algae Vaucheria litorea are able to carry out photosynthesis; however, isolated chloroplasts from V. litorea are not. Researchers have determined that the DNA within the chloroplasts contains the genes required for photosynthesis. Many of the additional genes needed to sustain chloroplast function are located in the nucleus. To investigate the genetic requirements for chloroplast function in the green sea slug, Elysia chlorotica, researchers sequenced the psbO gene found in V. litorea. The psbO gene encodes for part of the water-splitting complex in the light-dependent reaction during photosynthesis. The researchers then determined which cells, cell parts, and developmental stage of the green sea slug, if any, also contain this gene. The data from their investigation are shown in the table.

Which claim is most consistent with the evidence that psbO DNA sequences are detected in E. chlorotica eggs?
1 point
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The psbO gene is transferred from V. litorea when it is consumed by E. chlorotica.
The psbO gene was transferred from V. litorea to a recent ancestor of E. chlorotica.
The psbO gene independently evolved in response to selective pressure in an ancestor of E. chlorotica.
The psbO gene is present in all organisms belonging to the same phylogenetic clade as E. chlorotica.

Answer 1

The psbO gene was transferred from V. litorea to a recent ancestor of E. chlorotica.

Answer 2

The claim that is most consistent with the evidence that psbO DNA sequences are detected in E. chlorotica eggs is:

The psbO gene was transferred from V. litorea to a recent ancestor of E. chlorotica.

Answer 3

The most consistent claim with the evidence that psbO DNA sequences are detected in E. chlorotica eggs is:

The psbO gene was transferred from V. litorea to a recent ancestor of E. chlorotica.

This claim is supported by the fact that the psbO gene, which is involved in photosynthesis, is present in the eggs of E. chlorotica. This suggests that the gene was transferred from V. litorea, which is known to have the genes required for photosynthesis in its chloroplasts. The presence of the psbO gene in the eggs indicates that it has been inherited from a recent ancestor of E. chlorotica.